The Zombie Mice who 'scalp' and eat albatrosses alive on Marion Island

Only those who know what to look for will spot the clues pointing to the grisly attacks that took place the night before.

When the sun goes down, under cover of darkness, millions of tiny mice emerge from their burrows and stalk across this bleak and inhospitable volcanic island, located in the southern Indian Ocean, halfway between South Africa and Antarctica.

WARNING: Graphic image below

Scientific researchers have a name for these Marion Island rodents: Zombie Mice.

The Marion mice earned this horror movie-esque moniker because of their deadly gnawing attacks on nesting albatross and their helpless chicks.

Night vision footage of this unusual phenomenon is disturbing. Small packs of flesh-eating zombie mice swarm over the nesting adult albatross and the fluffy chicks. The brown mice perch on top of a victim's head and gnaw right through its flesh.

"They're scalped," Angel says.

"The mice are constantly on the birds at night - on their heads, in their eyes and crawling all over them.

"The chicks can barely move. They've got these wounds that are festering and open on their abdomen. It is harrowing to watch and you know it is going to die. It is heartbreaking."

Except for a hardy group of scientific researchers, like Angel, who live on the island for stretches of up to a year at a time, Marion is uninhabited by humans.

But, as Angel and her team conduct patrols of the albatross colonies across the 298 square kilometre island, they know exactly how to spot where the zombie mice have been active.

"You know the birds [that have been attacked] because you can easily distinguish them," she says.

"During the day the birds are very alive. They're flapping their winds, they're practicing to fly. They are active. So, when you see some of them just sitting there, doing nothing, you know. You walk up to them and there is a wound somewhere.

No one is certain when mice first landed at Marion Island, which is a little smaller in size than Malta.

It is widely assumed the first few mice came to Marion with seal hunters in the early 1800s. When the hunters left the island, the mice stayed on and started a colony.

Aside from the mice and albatross, hundreds of thousands of seabirds live on Marion. It is a paradise for the birds. The island's craggy shoreline is sprinkled with seals and sea lions. Pods of killer whales lurk in the cold swells that sweep up from the Antarctic. The animals on Marion see fewer than 100 humans a year. You can only reach the island by ship. There are no harbours to anchor up. Helicopters must take off from ships and fly the final leg.

All the animals co-existed peacefully on Marion, until around the early 2000s. Then, winters started to get warmer. Under these changing conditions, more mice survived the winters. And in drier and warmer summers, the mice multiplied.

"In winter, the mice are beyond starving," Angel says.

"If you put out traps in winter the mice will cannibalise and eat the ones which have been caught."

Ravenous with hunger, the mice on Marion began to attack the nesting albatross – adults and chicks.

"There are millions of mice," Angel says.

The density of mice fluctuates depending on elevation and habitat. Angel's team calculate most live in the island's biotic regions, where the seals breed and there are animal scraps to feed on.

"What will make Marion challenging is its size. When it is done it will be the biggest island ever eradicated of mice."

Bait specially prepared to kill the mice will be dropped by three helicopters flown by highly skilled pilots who must keep flying in continuous shifts until the entire island has been covered in one go. If a small patch of land is accidentally missed, mice could survive and regenerate the colony.

Complicating matters, the bait drop must happen in winter. For an island situated in the Roaring Forties, a belt of ferocious and hostile weather above Antarctica, the ramifications are clear.

"The majority of mice attacks happen in winter time, because of food scarcity on the island," van der Merwe says.

"And that is also why the eradication must happen at winter so the mice will be more likely to go for the bait.

"The problem with this is that you are dealing with weather. And weather on this island is no joke. We really need the weather to be on our side.

"You have very small windows when conditions are optimal for flying and distributing the bait."

South Africa's Department of Environmental Affairs will lead the project, but financing is a problematic burden. The bait alone is expected to cost more than $3 million. A support vessel is required to transport three choppers to the middle of nowhere, and a multi-skilled team must also be assembled.

"You want the least amount of the people there as possible. The more people the more logistical issues you have to manage," van der Merwe says.

The team plans to have around six bait stations spread around the island. The helicopters will dump their mice-killing payloads and return to these bases for more bait. Flying choppers this far south, when 140 knot winds in winter are commonplace, is fraught with risk. Weather can change quickly and dramatically.

Meticulous planning is underway, van der Merwe says.

"You get one chance. There is no do over. It's too much money and it takes too much time," she says.

"Money is a big problem … from a South African point of view, we have a lot of other struggles in our country. It's difficult to ask people to give money towards a very remote area that has no significance in their day-to-day life and they don't understand the ecological importance of these islands."